avz

Indeed. For comparison: atoms are about four orders of magnitude larger than atomic nuclei. The size of the former is generally a few tens to low hundreds of picometers (1 pm = 1e-12 m) while the size of the latter is just a few femtometers (1 fm = 1e-15 m).

See, e.g. https://en.wikipedia.org/wiki/Atomic_nucleus for concrete example sizes.

There is a palpable difference between the universe described by many religions and the universe described by science. The former is all built from concepts rooted in human society such as father, son, judgment, commandment, obedience, sacrifice, punishment etc. The latter is built from eerie ideas such as force field, wavefunction, observable, reference frame, superposition etc. The former feels small, ordinary, familiar and manmade. The latter feels like we're fumbling for words to describe something that fundamentally transcends ordinary human experience.

BTW: The numbers involved in each description are also telling. Those used by religions are often small and comfortable for a human mind, e.g. ten commandments, seven days of creation. Even the supposed large numbers such as 144,000 never come close to what you need to describe nature such as the number of stars in our galaxy (around 10^11) or the number of atoms in a human body (order of 10^27). See physics constants for even better examples. Also, religions often describe reality using numbers that look suspiciously memorable in decimal notation. OTOH, nature never gives us round decimal-friendly numbers for constants. I think this also makes religion feel manmade and science authentic.

> The author TOTALLY misses the point [...]

OTOH, you're failing to comprehend what the key word - nothing - means :-) Look here:

> how if there was at one point nothing, how is there now something?

See, you're imagining two points in time. Some stuff exists in the second moment, but not the first. However, since you're saying "one point" and "now" you are assuming that time exists in both instants. But if time exists then this is already something and not nothing. The true nothing excludes time, space and all the junk in it. Nothing is really just

> Was the response perfect? Certainly not.

No, it was not perfect. According to [1] the US has 27% of all cases of COVID-19, 24% of all COVID-19 deaths and 29% of new cases yesterday. For comparison US has 4.3% of world's population [2].

> Did some other countries do better? [...] it just means that you have only been exposed to Scandinavia and/or Singapore

Did some countries do worse? Italy is often cited as a badly hit country (and is not Singapore nor in Scandinavia), but if you look at their total cases curve [3] you'll see it has become nearly flat and new cases have been suppressed to near ~200/day from the peak of ~6k/day. For comparison, the corresponding plots for the US show a bungled attempt to flatten the curve followed by renewed exponential growth [4]. Daily new cases were only suppressed to ~1k/day from the peak of ~2.7/day.

> Does this make the US a "totally failed shit-hole state"? HELL NO!!

Well, what are the inclusion criteria? I'm asking, because when it comes to COVID-19 the US is doing so badly that now only 26 other countries have had more cases of COVID-19 since the beginning of the pandemic than the US added yesterday (73,388) [1].

[1]: https://www.worldometers.info/coronavirus/

[2]: https://en.wikipedia.org/wiki/World_population

[3]: https://www.worldometers.info/coronavirus/country/italy/

[4]: https://www.worldometers.info/coronavirus/country/us/

Reaction wheels saturate and are therefore more suited for precise attitude control than as a source of sustained torque. Once they saturate you need to unload the accumulated momentum via some other mechanism. Thus, you do need a second propulsion system such as thrusters, light sail etc.

As with the compass, the orientation of your magnetic dipole against the field is unstable, so now you need a second propulsion system for maintaining the unstable orientation of the dipole.

To highlight the persistence of the confusion compare the confusion matrix in two wikipedia articles: [1] and [2].

[1] https://en.wikipedia.org/wiki/Confusion_matrix

[2] https://en.wikipedia.org/wiki/Pre-_and_post-test_probability...

(In case edits are made one way or the other: both articles display similar confusion matrices but disagree on the names of the off-diagonal elements. In [1] false positives are called "type I errors" and false negatives are called "type II errors". In [2] false positives are called "type II errors" and false negatives are called "type I errors".)

(Edit: layout)

The reason the practice of collecting consumer data is so prevalent is that it is very easy to do and opens potential opportunities for the business in future. Never mind that it exposes consumers to risks.

The practice won't stop until consumer data becomes a liability for any business touching it. At that time, only businesses that are actually able to utilize the data to derive revenue sufficient to compensate the liability will continue to collect it. Hopefully, in many cases the revenue would come about as a result of creation of some value for the consumer.

> The problem is that the west has nobody in power with living memory of a pandemic. [...] there hasn't been a pandemic in the west in over 100 years...

Recent counter-example:

https://en.wikipedia.org/wiki/2009_flu_pandemic

https://en.wikipedia.org/wiki/2009_flu_pandemic_in_the_Unite...

Key stats:

* global cases: 700 million - 1.4 billion

* global deaths: 150,000–575,000

* US cases: 60.8 million

* US deaths: 12,469

A few more counter-examples can be found here: https://en.wikipedia.org/wiki/List_of_epidemics

(Edit: added key stats)

Another counter-point to the inhumane position you're rebuking - one which speaks to people's self-interest - is that as the healthcare systems become overwhelmed they will eventually stop treating conditions and accidents which afflict everyone including young people.

I recently attended a virology lecture where this question was asked.

The answer was that this is very unlikely. In fact, the evolutionary direction of all known viruses is the opposite: from high towards low virulence. High virulence is observed in viruses which have recently jumped from one species to another and can be thought of as temporary maladaptation to the new species. As the virus adapts, the damage it does in the course of its reproduction process becomes less and less severe. Eventually, many viruses end up causing mild symptoms similar to the common cold, warts etc.

That's OK. Assuming the universe is finite or countable, the number of all possible circumstances in which a real number needs to be described (e.g. a practical problem needing solution or somebody's curiosity needing satisfaction) is also countable. In other words, most real numbers will never come up in any situation in the entire history of a countable universe.

This is not a correct summary of the article!

The article never suggests or discusses the potential of the bureaucratic problems at the HHS and the resulting delays to stoke or support conspiracy arguments. On the contrary, that part appears to be OP's own reflection on the subject and should not be attributed to New Yorker.

Source: Just finished reading the full article.

When I was a nerdy teenager I imagined that by a date like 2020 humankind would have cured cancer, built a base on the Moon or Mars, eradicated infectious diseases and taken control over climate and weather. It turns out that in the real world progress is a lot slower than in the imagination of a sci-fi-imbued teenager. It turns out that solving problems takes work. A lot of it.

If people work less, especially if engineers, scientists, doctors etc work less, then technological progress will be taking place slower than it is currently. The disappointment of my teenage self with 2030 will then be even greater than that with 2020.

I'm genuinely puzzled by the general anti-work sentiment I perceive on HN (maybe my perception is simply incorrect). I'd expect that most folks here work as engineers or in a similar field that rewards with interesting and meaningful problems and that a substantial fraction had once been sci-fi-imbued teenagers like myself and possibly feel the same disappointment with the pace of technological progress.

I'm very worried that the anti-work movement is (inadvertently?) pushing on the breaks of technological progress :-(

Several countries in the EU (e.g. Nordic countries) offer single-payer healthcare services and the EU does have freedom of movement, so such a step wouldn't really be "unprecedented".

Probably because diffusion, air currents, stratospheric jets, winds and other climate phenomena are not contained by national borders.

> A simulation, at least as we'd understand it, would mean some kind of set variables and set rules. It would be entirely deterministic

Why would the simulation be entirely deterministic? The simulations humans run often are not, see e.g. Monte Carlo simulations [1]. Also, the laws of physics as we presently know them are not completely deterministic either [2].

[1] https://en.wikipedia.org/wiki/Monte_Carlo_method

[2] https://en.wikipedia.org/wiki/Measurement_in_quantum_mechani...

> They tell the self-learner that solutions aren't provided because everyone has the ability to know if their solutions are correct without having their work checked. Would you write a complicated program and write no test cases, or could you instantly know your program is bug free the first time you write it? Why is math suddenly any different?

Math is an art of making a specific type of rigorous, formal arguments that are meant to convince, beyond all doubt, another human being that one statement follows from another. If an argument like that fails to convince even the proof author themselves, then you know the argument isn't good even without comparing it to another solution.

In practice, after you've written down your proof, you examine it for weak spots. If any particular step raises doubts or objections then you recursively spell it out in greater detail (or replace with an alternative approach) until eventually all doubt dissipates. At that point you don't need to compare it to another solution.

In fact, as you recognized yourself, your solution is likely to be different from the book author's, so comparison isn't helpful. Similarly, a problem like "write a small application to..." in a coding book or an assignment like "write an essay on..." in a writing book don't include solutions. Code, proofs and essays are all too free-form to subject them to correctness verification by comparison with a standard.

Perhaps what you have in mind are examples. All good math textbooks include worked-out proofs that illustrate the techniques. In fact these are generally the bulk of the book! Perhaps you're asking for more examples. That's fair. Proof problems OTOH should be given without solutions to encourage independent creative thought of the reader and to avoid incorrect implication that there is the single correct solution.

(Disclaimer: Not a mathematician.)

> 5. In order for the market rate price of housing to become affordable to cooks and servers, it would first become dirt cheap for tech workers making 2-4x their compensation. Therefore all of that worldwide demand for SF tech worker housing would need to be satiated before the market solves this problem.

Suppose you take a fraction S of city's residential surface area and build it up by H times average residential height. Housing volume increases by S * H. Most housing in SF is merely 2 stories high. Let's assume average is 3 stories. Now, pick 1% of city's residential area and build it up by adding 30 stories, say from 3 to 33. Note that 33 stories is actually smaller than a few existing tall residential structures in SF [1]. This would give relative increase in housing volume by S * H = 1% * 10 = 10% which given SF's population of >880k [2] amounts to >88k increase in housing capacity. This is more than the entire global workforce of Google [3].

It's a lot of construction work, of course, but it looks feasible. Many cities build a lot higher and on a wider area than the figures above.

[1] https://en.wikipedia.org/wiki/Category:Residential_skyscrape...

[2] 884,363 (2017), https://en.wikipedia.org/wiki/San_Francisco

[3] 85,050 (Q1 2018), https://en.wikipedia.org/wiki/Google

Edit: formatting and correction

I think the core issue here is that people want two things. On one hand we want our models to accurately describe reality, not an idea of what reality should be. On the other hand, we don't want ML to freeze society and culture in their current state, but to help decide on and drive social change. The tension between these goals arises when models trained today are used to make decisions tomorrow.

One way to resolve the tension might be to add time dimension and historical training data. The models might then be able to return in addition to any prediction variable p also its time derivative dp/dt. For example, a model might then return results such as: "movies with female main character: lower sentiment, trending up; movies with male main character: higher sentiment, trending down".

> Unless the cable had absolutely no temperature expansion...

One might be able to get a composite with very close to zero thermal expansion coefficient by linking stages made of materials with positive and negative [1] coefficients.

[1] https://en.wikipedia.org/wiki/Negative_thermal_expansion

> I haven't seen anyone attempt to address the issue of how you "land" in the atmosphere without touching down on the surface?

Spacecraft in the Venera program successfully deployed balloons following atmospheric entry, see [1]. The balloons stayed up in the atmosphere for more than 46 hours.

> how do you launch a rocket within the atmosphere?

Atmospheric launch into a suborbital trajectory was demonstrated by White Knight, see [2]. There exist air-to-space missiles, see [3]. Admittedly, none of these are fully fledged space launches from the atmosphere, but they show it's not entirely outside the real of the plausible.

[1] https://en.wikipedia.org/wiki/Vega_program#Balloon [2] https://en.wikipedia.org/wiki/Scaled_Composites_White_Knight [3] https://en.wikipedia.org/wiki/ASM-135_ASAT

Parents' primary responsibility is to ensure that the environment in which their kids grow up, the food they eat etc promote healthy development. For many practical purposes, the kids' protein-building machinery including the nucleic acids, can be treated the same way as the environment, the food etc - another critical input to a developing human life.

In this view, it is scarcely surprising that parents would want to give their kids viable genetic information just like they want to give their kids a good home, healthy food and challenging education.

This desire to ensure the good of the kids is a strong force pushing humanity forward and I see no reason to object.

Unequal access to shelter, food, education or genetic techniques is a different matter. But our failure to ensure universal access to the spoils of a new invention does not imply that there is something wrong with the invention. The real problem is more like the lack of compassion for other folks...

So let's not throw the baby out with the bathwater.

I don't think that's necessary. The loss of atmosphere by Mars may have been significant on the timescale of its five-billion-years history, but not on the timescale of a human settlement project.

The mass of the Martian atmosphere is about 25 teratonnes [1]. According to the measurements by MAVEN, the rate of mass loss by Martian atmosphere due to solar wind is 100 g/s [2]. At this rate it would take

    25e12 * 1000 * 1000 * 0.01 / 100 / 3600 / 24 / 365.25 = 79 million years

for Mars to loose 1% of the mass of its atmosphere. Even if the rate of mass loss were 10 times higher than measured by MAVEN (it's known to increase during solar storms and in perihelium), it'd still take nearly 8 million years.

Looks like if we can increase density and pressure of Martian atmosphere as GP suggested, we don't really need to worry about the lack of magnetospheric protection.

[1] https://en.wikipedia.org/wiki/Atmosphere_of_Mars [2] https://www.nasa.gov/press-release/nasa-mission-reveals-spee...

> [...] sticky total # of jobs. As women further enter the workforce, the mean household income will trend towards double income, and the labor pool will be contested with more applicants, in both cases rendering a male applicant at a substantial disadvantage (comparatively to history).

Isn't this the lump of labor fallacy [1]?

I think the economic theory leads to a different description: As more women enter the workforce, the aggregate income goes up. Some of it is spent and becomes someone else's income. Some of it is saved in a bank which loans it out or invests it. The receiving business then spends it and once again the money becomes someone else's income.

IOW, as more people work, both aggregate demand and aggregate income rise. The economy shifts into a higher gear.

[1] https://en.wikipedia.org/wiki/Lump_of_labour_fallacy

Hopefully automation will reduce the need for humans to do the boring, repetitive jobs and increase the number of people working in jobs they find rewarding and interesting. I doubt we could eliminate the former completely and have everyone doing the latter, but it seems that automation may improve the ratio significantly.

> As the author points out, we've forgotten how to be bored. We need to learn to engage that part of our brain again.

This sounds like a contradiction. Isn't boredom precisely the state that results when one fails to engage their brain?

It does mean that indeed!

Note for example that in a gravity field like the one near the Earth surface the "down" direction has very different properties than the two horizontal directions (1).

In particular, an object stationary with respect to the surface released at altitude will develop linear momentum in the down direction, so in the down direction momentum is not conserved. OTOH, the linear momentum in any of the horizontal directions is conserved.

(1) Isotropy means that space has the same properties in all directions.

I believe they talk about the computational task described in [1] (published in 2016). Note that this is somewhat contrived: it's a task defined specifically so that it is very difficult for classical computers and relatively easy for quantum computers. It is also defined in a way that ensures that a quantum computer necessary to demonstrate quantum supremacy is relatively small in terms of the number of qubits.

The task is that of generating output samples from pseudo-random quantum circuits. The paper shows that the task has exponential computational complexity on classical computers and that it can be used to demonstrate quantum supremacy using a quantum computer with approximately 50 qubits.

Now, the IEEE Spectrum article indicates that the team has now built a 49-qubit quantum computer and plan to use it to demonstrate quantum supremacy.

EDIT: Replaced direct pdf link with the article page link.

[1] https://arxiv.org/abs/1608.00263

> You have to go out of your way to find a language where "tea" deviates from those patterns.

Well, there you go:

Lithuanian: arbata, https://translate.google.com/#en/lt/tea

Polish: herbata, https://translate.google.com/#en/pl/tea

Aymara: pulu, https://ay.wikipedia.org/wiki/Pulu